Major research emphasis again, in this final grant year, will center on the toxic stress metabolites produced by the sweet potato, Ipomoea batatas, in response to fungus infection and other injurious stimuli. Studies will be made of the histopathological features of the pulmonary disease produced in mice and rats following injection of the edemogenic agent, 4-ipomeanol. The lung-toxic agents also cause tubular nephrosis in mice that survive the lung disease. The mechanism of this nephrotoxicity will be explored along lines used in studies on the mechanism of pulmonary attack. The response of bovines to pure 4-ipomeanol will be determined using synthesized toxic and lethal levels, and a complete study of the gross and histopathology in this species will be made. Work is to continue in the attempt to develop relatively simple qualitative and quantitative analytical methodology for 4-ipomeanol, 1-ipomeanol, and 1,4-ipomeadiol. If successful, the procedures will be applied to ascertaining the levels of these lung toxins in sweet potatoes available for purchase in local food markets. They will also be useful in projected studies on the possible relationship between the lung toxins in sweet potatoes of New Guinea and the incidence of chronic lung disease in Highland natives whose diet includes large amounts of sweet potatoes. The tremorgenic mycotoxin, penitrem A, from Penicillium crustosum will be studied further as a potential inhibitor of glycine formation in the central nervous system and in relation to its reported prolongation of life in tumor implanted mice. Other projected mycotoxin research relates to screening studies for causative agents and toxigenic fungi responsible for unusual or particularly devastating diseases of livestock. The suspected feed samples are provided by veterinary diagnostic laboratories and by veterinarians in private practice.